Help with Starship Excalibur fin strength

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I have been practicing with paper and CA on scrap balsa. It definitely adds rigidity
 
I have been practicing with paper and CA on scrap balsa. It definitely adds rigidity

I did papering using white glue and paper a couple of times early on. One time, I got interrupted after papering only 1 side and didn't come back to it until the next day. The fins were warped.

I 100% believe it could be that I was not using an optimal technique, too much glue or whatever. I didn't have that issue when I papered both side and pressed under a heavy weight. Not going to be easy to do that on the assembled rocket, though. . .

Glad to hear you're liking the improvement!

Sandy.
 
I did papering using white glue and paper a couple of times early on. One time, I got interrupted after papering only 1 side and didn't come back to it until the next day. The fins were warped.
I use paper and yellow wood glue, but this requires that you paper both sides and then clamp between 2 flat surfaces while the glue dries. I have to do this fast. I have to do this carefully so I get on enough glue but not too much. And the biggest problem is that I end up with dried glue on the edges that is hard to sand off and when you sand it off you end up with fuzzies where the paper meets the airfoil on the edge of the fin. I'm sure I could up my technique, use CA, be more careful with cutting out the paper, and get better results. I'm not sure I want to put that much more effort into it.
 
Well, I papered the fins with CA. Looked pretty good until I painted. Now it looks hideous. But, the fins are strong now. But, looks awful. I am ashamed.
 
Post a pic - don't be embarrassed. You tried a new technique and it wasn't flawless the first time. Maybe some of us on the forum have had a similar issue (for sure we've all had a ton of finishing failures!) and can help you recover. I learn more from my failures than my successes. I learn A LOT!!! :)

Sandy.
 
Hideous!

sprayed three light coats - Krylon enamel white.

I used to fly RC model helicopters and still have some blade covering. Thinking of using it to recover the fins after painting. I think maybe the paper that was soaked in CA and dried soaked in some paint and expanded.
CleanShot 2022-04-03 at 18.53.30@2x.png
 
Hideous!

sprayed three light coats - Krylon enamel white.

I used to fly RC model helicopters and still have some blade covering. Thinking of using it to recover the fins after painting. I think maybe the paper that was soaked in CA and dried soaked in some paint and expanded.
View attachment 512636
OK, you have multiple issues there. Here's what I can identify, please take this constructively. Painting is an endless journey. I mostly achieve decent results but I still consider myself to be a neophyte in many ways.

First, regarding the papering:
1) Normally, obviously, you would paper the fins before assembly, and that would give you the opportunity to smooth the edges and create a seamless appearance. So you were down a touchdown before you got the ball here.
2) Along its right vertical edge, the paper appears to not be laying flat against the fin. Again, when papering on the bench (before assembly), you would normally press the fins while drying to ensure that the paper lays down perfectly flat.

About the paint itself:
3) Did you use any primer? Did your fins have any filler or sealer applied (other than the paper), or were they bare wood? Bare balsa is not a good receiver of paint, generally.
4) The paint looks to me like it was applied rather heavily... not so sure about "light coats*. Isn't that a run at the top left of the fin? Over-painting of fins is something that I have frequently struggled with, I know that problem quite well.
5) The paint on the body tube appears to be a bit bumpy as well.

Collectively, I would say that (a) you should focus a bit more on surface prep. A smooth, well-prepared surface will contribute greatly to a smooth painted finish. And (b) lighter, more even strokes with the spray.

Of course, how much effort you choose to put in depends entirely on how finicky you are about the final appearance. Some folks don't bother to paint at all, others (I won't name names) spend many hours wet-sanding and polishing to achieve a true mirror finish. I fall somewhere in the middle.
 
Hideous!

sprayed three light coats - Krylon enamel white.

I used to fly RC model helicopters and still have some blade covering. Thinking of using it to recover the fins after painting. I think maybe the paper that was soaked in CA and dried soaked in some paint and expanded.
View attachment 512636

I am far from a pro on finishing. I usually use matte paints vs. gloss to hide some of my sins and stickers to cover the rest!!!

It looks like you have a high gloss Krylon paint and it accentuated small issues into big issues and also it looks like the paint didn't lay down as well as you'd want. Maybe humidity, age of paint, temperature, surface prep, + million other possibilities.

As to the fix, I'd say you figure out where you want to be and weigh that vs. the time to do a fix. First off, if you plan to sand anything, I'd make triple sure the paint is fully cured. If you start sanding paint that is not completely cured, everything gets a ton worse, so put it in the sun and let it get cured. The options I see (hope others comment to give other solutions too) are:

1: Call it a learning experience and leave it as is. I'm sure it will still fly fine and the paper will definitely help it last longer.
2: Minor correction (after paint is cured) using a razor as a scraper to knock down the biggest issues. Scuff sand and high build primer, then new paint.
3: After the paint is VERY cured, sand most down, being careful not to scuff the paper as fuzzies are another level of misery. Add some lightweight filler, high build primer, sand, repeat a few times and when you're tired of playing, new paint.

IMO, the risk associated is also in the order presented. #1, minimal risk, you'll own and fly the rocket for years. #2, it'll look a bit better and you'll get 4-8 flights out of it before something bad happens. #3, you'll spend a lot of time waiting for it to fully cure, way too much time sanding, you'll end up getting fuzzies and having to repair that and finally, after it looks like a million bux, the first motor you put in will CATO. . . it is the way of the world. . .

Personally, I'd opt for #1 (maybe go ahead and play with colors and decals) but just let it go. If you can find a rocketeer that can pick out the issues at safe flight distances and can comment on them while the rocket is flying a perfect flight at speed, then they have better eyesight than I ever did. Enjoy the rocket, learn from what didn't work out as anticipated and just build another one and find new problems. If you didn't like building stuff, you'd buy RTF. If you didn't like learning yourself, you wouldn't be doing a hobby at all.

Sorry the finish isn't what you wanted, but so far, I've not scrapped a rocket due to bad finishing. They still fly fine and people still like to see them fly on your dollar vs. theirs!!!

Sandy.

PS: I just thought of another option. . . make it a feature, not a problem. Rockets fit into the steampunk theme fairly well. I recall seeing some awesome steampunk rockets over the years. Take advantage of the finish issues you see, add some glue bumps to look like rivets, add some thread to look like joints between pieces of metal, paint it mottled brass, gray, copper, silver, gold, do a wash over the whole thing and when people are oogling the finished piece, just smile and say "yep, that was my plan all along. . . " To be clear, I'm not making a joke. A steampunk finish would convert any problems into design elements. Not everybody likes the style, but on rockets, I do!

I tried to find my steampunk rocket, but the trailer is a wreck and I couldn't get in far enough to search the boxes. This guy went way over the top and it is 100 times better than anything I would do, but mine wasn't too bad and always got good comments. https://www.rocketryforum.com/threa...acme-spitfire-build-a-work-in-progress.64169/

Just a 4th direction to consider if you think the style is fun. I'm pretty sure I'm going to do another one sooner than later as I'm excited about it again!

S^2.
 
Thanks for the advice. I am so mad at myself. But I might just fly it. My son suggested a grinder - ha ha. I do have a dremel tool I could sand it down with… believe me I considered it for half a second.
I just paid so much to get the parts and plans...
 

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